A method for depositing thin film layers on to surfaces modified with organic functional groups and products formed thereby is disclosed in published PCT application WO 91/17286. Refinements of the method are disclosed in Bunker, et als. Ceramic Thin Film Formation on Functionalized Interfaces Through Biomemetic Processing, Science, 264, 48-55 (1994) and Rieke, et als, "Biomemetic Thin-Film Synthesis", in Supramolecular Architecture: Synthetic Control in Thin-Films and Solids, T Bein ed., American Chemical Society, Washington D.C., 61-75, (1992), and in "Bioactive Void Metal Compositites For Orthopedic Implant Devices," Campbell, et als., National Research Society Proceedings, 414, 177, (1996).
In the process for providing a film product, an underlying substrate of a first material is chemically modified on at least one surface by attaching functional groups which provide nucleation sites for inducing crystallite growth of an inorganic second material on the underlying substrate, and contacting at least one chemically modified surface with a liquid solution of precursors of the inorganic second material for a sufficient period of time for the crystallite growth of a second material formed from the precursors of the inorganic second material in the liquid solution onto the modified underlying substrate by nucleation of the second material on the nucleation sites thereby forming inorganic crystallite second material growth onto the nucleation sites, the nucleation sites being chemically attached to the underlying substrate. Materials that mimic biological materials such as porous metal composites coated with hydroxyapatite have been produced by this process.
Processes for delivery of biologically active molecules such as bone morphogenic proteins have also been previously disclosed. See for example U.S. Pat. No. 5,385,887 and references cited therein. However the incorporation of biologically active materials, such as proteins into thin-film coatings has not previously been demonstrated. Release of such incorporated materials has not previously been suggested.